Front Cover (Phys. Status Solidi B 3/2010)

Is quantum criticality a key to unconventional superconductivity&quest; The observation of superconductivity in the vicinity of a magneti-cally ordered phase prompts an idea that quantum fluctuations associated with a magnetic quantum critical point may provide the glue to form superconducting electron pairs. Often, however, a superconducting phase veils the presence of a quantum critical point, making it difficult to prove or disprove the conjecture. In their article, Tuson Park et al. report measurements of the electri-cal resistivity of CeRhIn5 at its optimal pressure where the super-conducting transition temperature is a maximum. When super-conductivity is suppressed by a magnetic field, these experiments provide evidence for the presence of a putative quantum critical point. For the complete article go to page 553.